Experiments are being conducted on whole corneas obtained from normal and vitamin A deficient animals. The corneas were radioactively labeled in organ culture and the epithelial glycoproteins were separated by gel electrophoresis. 3H glucosamine labeling shows that repleting vitamin A deficient rats with retinoic acid restores the synthesis of three major glycoconjugates to normal levels within 24 hours. Repletion with excessive levels of retinoic acid further stimulates the synthesis of these glycoconjugates by the corneal epithelium.